Problems

[Heinz K. <kir...@df...>]

I had some problems here with lirc on a new dual AMD motherboard
Tyan 'Tiger MP S2460'.
In consequence of loading the lirc_serial module via 
'insmod lirc_serial' I happened to experience a total kernel lock 
that could only be solved by pressing the 'reset' button.

Having a look at the kernel sources I noticed, that the sense probing 
part of the code was responsable for the kernel lock (i.e. kernel 
function sleep_on_timeout did obviously block) and using
  'insmod lirc_serial sense=0'
solved this problem, i.e. the module was loadable now.

Nevertheless the lircd did not function properly: the first call of 
e.g. 'rc SEND_ONCE ...' did function properly but obviously locked up 
the lirc daemon, so that after this call:
a) any call of 'rc SEND_ONCE ...' failed with timeout
b) lircd was not stoppable any more
c) lircd could not be killed any more (even -9 failed)
d) 'rmmod lirc_serial' failed (module in use)
e) Shutdown of the system was no longer possible (probably as a 
   consequence of d), reset button to be used instead

Some further examination of the source code found the function 
lirc_poll using kernel function poll_wait to be blamable for the hangup. 
Desperately looking for a solution I decided to comment out the 
corresponding 'poll_wait' function call and could indeed solve the 
problem for me, since the module did not lock any more and 
functionality (in my case simply as a remote control device) did not 
seem to be restricted (exhaustive tests on this are still missing).

Nevertheless I have a bad feeling about this and so I decided to report 
this as a bug and ask for better solutions (if available). Perhaps 
there might be similar known problems with newer dual AMD boards?

For the sake of completeness:

system configuration:
  Linux SuSE 8.0 (standard SMP kernel)
  Tyan Tiger MP S2460 motherboard
  2 x AMD Athlon(tm) MP Processor 1800+
  512 MB DDR-Ram

Note: all the above phenomenons could be observed using lirc-0.6.4 as 
well as lirc-0.6.6. Nevertheless I had some problems using version 0.6.6 
since I could not get the 'rc ...' calls to function properly so I used 
version 0.6.4.

Please reply to my email address since I'm not subscribed to this list.

Heinz Kirchmann


-- 
Heinz Kirchmann
DFKI - Deutsches Forschungszentrum fuer Kuenstliche Intelligenz GmbH
       Postfach 2080, D-67608 Kaiserslautern
Tel: (+49 631) 205-3844
Fax: (+49 631) 205-3210
E-Mail: kir...@df...
--